An organic light-emitting diode (herein after referred to as OLED) display has many advantages such as self-illumination, fast response speed, high contrast ratio, wide angle of view and so on. The OLED has been applied in a display apparatus more and more widely.
Since a size of a conventional OLED display is not very large, length of each power supply wire between a power source in a power supply circuit and each pixel point is not very long, that is, a resistance value of the respective power supply wire is very small. Therefore, in operation process of the OLED display, resistance drop (IR drop) on the power supply wire of the OLED display is very small, and thus voltages of respective pixel points are almost consistent, and each pixel point emits lights having same luminance. Therefore, the problem of non-uniform lumination of the OLED display does not exist. However, as the size of the OLED display becomes large increasingly, it would cause the length of each power supply wire between a power source in the power supply circuit and each pixel point to increase, that is, the resistance value of the power supply wire increases, such that the resistance drop (IR drop) on the power supply wire of the OLED display increases in the operation process of the OLED display. As a result, voltages of pixel points of different areas in the OLED display are inconsistent, and pixel points of different areas emit lights having different degrees of lumination, thereby causing non-uniform luminance of the screen of the OLED display in the operation process.